Your Ears

Causes of Hearing Loss in Adults

Presbycusis:
This type of hearing loss is a result of the aging process. It results in a degeneration of the inner ear and tends to be progressive in nature. It is usually not noticed until later in life when high frequency hearing loss results in a decreased ability to understand speech.

Noise Induced Hearing Loss:
Prolonged exposure to harmful levels of noise can cause permanent damage to the hair cells in the inner ear resulting in irreversible hearing loss. It usually develops gradually over time and is not noticed until the high frequency hearing loss results in a decreased ability to understand speech. Sometimes, a single exposure to very high levels of sounds or impulse noises can cause acoustic trauma to the cochlea and result in hearing loss due to the damage sustained in the inner ear.

Trauma:
Examples of trauma that can result in permanent or temporary hearing loss include temporal bone fractures and perforations of the ear drum from foreign objects, infection or sudden changes in air pressure (barotraumas).

Drugs:
Some medicines are ototoxic and can cause damage to the auditory system resulting in permanent hearing loss. Aminoglycoside antibiotics (streptomycin, neomycin, gentamycin), salicylates (aspirin) in large quantities, loop diuretics (lasix, ethacrynic acid) and drugs used in chemotherapy regimens (cisplatin, carboplatin) are all drugs which are known to be ototoxic and can cause hearing loss.

Otosclerosis:
This is a disease process that reduces the ability of the stapes (one of the three tiny bones in the middle ear) to move efficiently. Over time, this process results in a progressive conductive hearing loss that can often be treated with surgery.

Meniere's disease:
This disease affects the inner ear and can be associated with hearing loss, dizziness (vertigo) and ringing in the ear (tinnitus).

Acoustic Neuroma:
This is a benign growth on the acoustic nerve that can cause progressive Sensorineural hearing loss and tinnitus. It can be accompanied by a feeling of aural fullness and is often detected at an early stage.

Causes of Hearing Loss in Children

Children with hearing loss may feel isolated socially and unhappy in school.

They may have difficulty with all academic areas, especially reading and math. Children with untreated mild to moderate hearing losses typically achieve 1-4 grade levels lower than their peers with normal hearing and these gaps can widen as they progress through school. Children with untreated severe to profound hearing loss typically achieve skills no higher than the 3rd or 4th grade level. Most importantly, these children do not catch up without intervention. Their ultimate level of achievement is related to parental involvement and the quantity, quality and timing of the support services that they receive.

Facts:

More than 1 million children in the U.S. have a hearing loss, U.S. Public Health Service.
1990 5% of children 18 years and under have hearing loss, U.S. Dept. of Health and Human Services, 1991.
One in 22 infants born in the U.S. has some kind of hearing problem. One in every 1000 infants born in the U.S. has a severe or profound hearing loss, NIDCD, 1989
83 out of every 1000 children in the U.S. have a hearing loss that significantly effects their education, U.S. Public Health Service, 1990 Out of every 1000 school-age students in the U.S., 7 have a bilateral hearing loss and 19 have a unilateral hearing loss that may significantly interfere with their education, Berg, F.H., 1985
Among school age children, severe to profound hearing loss occurs in 9 out of every 1000 children, National Association of the Deaf, 1974 30% of children who are hard of hearing have a disability in addition to a hearing loss, Wolff, A.B., & Harkins, J.E., 1986

Otitis Media:
This is the most common cause of hearing loss in young children. Otitis media is an inflammation in the middle ear and is usually associated with a buildup of fluid behind the eardrum. This fluid, which may or may not be infected, causes a temporary, fluctuating conductive hearing loss hearing loss. This hearing loss may be mild to moderate in severity and result in speech sounds being muffled or inaudible to the child. In cases where otitis media occurs over and over again, permanent damage to the middle ear system and sometimes the hearing nerve can occur.

Effects of Hearing Loss in Children:
Hearing is crucial to speech and language development, communication and learning. The earlier hearing loss occurs in a child's life, the more serious the effects on the child's development. Likewise, the earlier the problem is identified and intervention begun, the less serious overall impact on the child. Hearing loss in children causes delays in the development of speech and language. Because they often cannot hear word endings or quiet speech sounds like "s", "sh", "f", "t", and "k", they don't produce them in their own speech and their speech may be difficult to understand. Their vocabulary develops more slowly, they have trouble understanding abstract words and words with multiple meanings and have difficulty producing and understanding complex sentences.

Methods and cost for Newborn Hearing Screening

Advances in technology for newborn hearing screening at most birthing hospitals have allowed for cost containment, with current charges ranging from $25 to $60. The cost of identifying a newborn with hearing loss is less than one-tenth the cost of identifying newborns with PKU, hypothyroidism, or sickle cell anemia, which are screened for in nearly every state. Currently, two types of electrophysiologic procedures are used to screen newborns singly or in combination:

Auditory brainstem responses (ABR) are measured by placing sensors on the baby's head. Sound is then introduced to the baby's ears through tiny earphones while the child sleeps. A computer allows brainwave activity to be recorded to indicate whether the ear and auditory brainstem pathway are responding to sound. This test is painless and takes only about 5 minutes.

Otoacoustic emissions (OAE) are faint sounds produced by most normal inner ears. The sounds cannot be heard by people, but can be detected by very sensitive microphones that are placed in the ear canal. During testing, a tiny flexible plug is inserted into the baby's ear and sound is then projected into the ear through the plug. A microphone inside the plug records the otoacoustic emissions that the normal ear produces in response to the incoming sound. Testing is also painless, takes about 5 minutes to complete, and can be done while the baby sleeps.

Benefits of (EHDI)

Infants identified with hearing loss can be fit with amplification by as young as 4 weeks of age. With appropriate early intervention, children with hearing loss can be mainstreamed in regular elementary and secondary education classrooms. Recent research has concluded that children born with a hearing loss who are identified and given appropriate intervention before 6 months of age demonstrated significantly better speech and reading comprehension than children identified after 6 months of age.

Even mild hearing loss can significantly interfere with the reception of spoken language and education performance. Research indicates that children with unilateral hearing loss (in one ear) are ten times as likely to be held back at least one grade compared to children with normal hearing. Similar academic achievement lags have been reported for children with even slight hearing loss. Children with mild hearing loss miss 25-50% of speech in the classroom and may be inappropriately labeled as having a behavior problem.

Recent clinical studies indicate that early detection of hearing loss followed with appropriate intervention minimizes the need for extensive habilitation during the school years and therefore reduces the burden on the IDEA Part B program. In contrast, a 30-year Gallaudet study revealed that half of the children with hearing loss graduate from high school with a 4th grade reading level or less.